Field of the Invention
The present invention generally relates to an electromagnetic flowmeter and, in particular to an electromagnetic flowmeter with adjustable electrode structures.
Description of Prior Art
An electromagnetic flowmeter usually measures a flow rate of a conductive fluid (such as water, etc.) by use of electromagnetic induction. The electromagnetic flowmeter is mainly composed of a measurement tube, a pair of electrode structures arranged on the measurement tube and a pair of coils. Additionally, a magnetic field is formed in the measurement tube and an electromotive force is generated between the electrode structures after the coils are energized. Therefore, the electromotive force of the magnetic field is changed when the fluid passes through the measurement body, and then the flow rate of the fluid can be calculated.
An electromagnetic flowmeter usually detects the fluid in the tube through the electrode structures. However, fluid in the tube might cause damages to detecting portions of the electrode structures. Therefore, failures or inaccuracies of measurement of the electromagnetic flowmeter might be occurred after using a considerable amount of time so that noises of the electronic signal are generated. In addition, metal shells of traditional electromagnetic flowmeter are mostly sealed by welding to avoid moisture penetration for ensuring normal operations of internal electrode structures and coils, but this welding process causes difficulty in replacing the electrode structures inside the metal shell. As a result, pipeline-related devices must be shut down to replace the electromagnetic flowmeter that results in disruptions of production, a lower capacity, and a high cost.
In view of the above drawbacks, the Inventor proposes the present invention based on his expert knowledge and elaborate researches in order to solve the problems of prior art.